The present invention relates to a sealing arrangement for a rolling-contact bearing, in particular groove ball bearing.
German patent publication DE 41 33 777 describes a rolling-contact bearing with an inner bearing ring, an outer bearing ring, and rolling elements disposed between the inner and outer bearing rings. The rolling-contact bearing is provided to support a tension roller of a belt drive, with a seal disposed on one side of the rolling elements and another seal disposed on the other side of the rolling elements. The seals are secured to the outer bearing ring and seal an annular gap radially bounded by the bearing rings, whereby each seal has a sealing lip for support against the outer surface area of the inner bearing ring. While the arrangement of these seals may in some instances be sufficient to inhibit ingress of contaminants into the rolling-contact bearing or escape of lubricant from the rolling-contact bearing, when, for example, installed in a tension roller for protection against splash water. However, this seal arrangement is ineffective for vehicles operated off-road operation and situations, when the vehicle is driven through water or subject to significant ingress of dirt into the installation space intended for the internal combustion engine. To tackle this problem, the use of lids has been proposed which are typically snapped on to the hub of the tension roller and completely cover the rolling-contact bearing on one side. Still, under more extreme situations, these lids proved to be unsatisfactory in order to provide an effective protection because moisture crept in via the snapped connection into the intermediate spaced bounded by the lid and ultimately migrated via the sealing lip into the rolling-contact bearing. Moreover, another shortcoming resides in the fact that the lid can be attached only on one side of the rolling-contact bearing.
It would therefore be desirable and advantageous to provide an improved sealing arrangement for a rolling-contact bearing to obviate prior art shortcomings and to enable a protection even under extreme situations.